Manually operated heating means for controlling automatic chokes



Dec. 13, 1966 Y J, G. POPE MANUALLY OPERATED HEATING MEANS FOR CONTROLLING AUTOMATIC CHOKES Filed Feb. 11, 1965 FIG.

FIG. 2

INVENTOR JOHN POPE ATTORNEY United States Patent M 3,291,461 MANUALLY OPERATED HEATING MEANS FOR CONTROLLING AUTOMATIC CHOKES John G. Pope, 12 Phillips Court, Shrewsbury, Mass. Filed Feb. 11, 1965, Ser. No. 431,894 1 Claim. (Cl. 261-39) This invention relates to a manually controlled heating device for applying heat to the bimetallic strip that controls the air-intake valve in an automatic choke for a carburetor for an internal combustion engine There has always been a problem of starting internal combustion engines having automatic chokes in cold weather. If the ignition is turned on and the operator steps on the gas pedal, the valve in the automatic choke often snaps shut, thus blocking out any entrance of air into the carburetor and preventing starting of the engine. It is necessary to open this valve to a certain extent in order to allow some air to enter the carburetor before the engine will start.

The present invention contemplates the utilization of a small inexpensive electric heating element located next to the bimetallic strip and being controlled as for instance from the dashboard of the car manually by the operator for such time as is necessary to heat the bimetallic strip sufficiently to cause the valve to open a sufficient amount to allow the air to enter the carburetor for ignition.

The invention also contemplates the use of a signal which is controlled by the valve in the automatic choke and this signal is energized only when the valve is in fully closed position, blocking off the air to the carburetor, and being deenergized immediately upon the opening of the valve, so that the operator of the car knows at once when the valve is closed and when it is open. It is only necessary to heat the bimetallic strip long enough to open the valve to allow air to come in for ignition purposes and this is usually in the neighborhood of fifteen seconds.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawings in which:

FIG. 1 is a view in elevation, partly in section illustrating the invention;

FIG. 2 is a plan view looking in the direction of arrow 2 in FIG. 1 with parts removed and parts being shown diagrammatically, and

FIG. 3 is a detail view looking in the direction of arrow 3 in FIG. 2.

In illustrating the present invention, the reference numeral discloses a representation of an air intake tube for a carburetor of.any description. This tube is provided with a flap valve of conventional design represented at 12. This is an automatic choke valve and it is turned by a shaft 14 under influence of a crank or similar member 16. This crank has a finger 18 which is held by the free end at 20 of a coiled bimetallic strip 22. This strip is coiled as well known in the art and when it expands under action of ambient heat it will turn the crank 16, thus turning shaft 14 and the flap valve 12 to a more open position to increase the amount of air which can be induced through the tube 10. On the other hand, cold will cause the spiral bimetallic strip to contract, thus moving the valve 12 in the opposite direction toward closed position.

The bimetallic strip 12 is fixed on a hub 24 in turn fixed in a plastic or similar cap 26 mounted on the fitting 28 in any desired manner, and according to the present invention a heating coil or unit 30 is provided in this cap just under the bimetallic strip and is preferably protected on the sides, i.e., from the plastic in the cap as well as the metallic strip 22 by a thin isinglass envelope so that regard- 3,291,461 Patented Dec. 13, 1966 less of the heat induced, in reasonable amounts, no damage is possible.

One end of the electric heating coil 30 may be attached to the battery or to any hot portion of the car and the other side is attached to a switch 32 preferably mounted on the dashboard of the car.

It will be seen that by closing the switch 32 at any time the electric heating coil 30 will be energized providing heat which will affect the bimetallic strip 22, thus causing the valve 12 to move from a closed to an open position. This motion is actually relatively small and not much heat is required as will be explained more fully hereinafter, but it is particularly pointed out that the heating element and the bimetallic coil are very simply and easily mounted in a single cap element which is applied to the fitting 28.

Referring now to FIGS. 2 and 3, there is here shown a relatively small lightweight plunger 34 mounted to slide rectilinearly according to the arrow in FIG. 2 in any kind of support diagrammatically indicated at 36. This plunger has provided thereon a pair of spaced pins 38, 38 which straddle a leaf 40 extending in a radial direction from the shaft 14. Aligned with one end of the plunger there is a push-button type of switch of conventional design indicated at 42 and this is provided with a spring 44 bearing against the end of the plunger 34 and normally holding it in the position shown in FIGS. 1 and 2. The push-button switch is adapted to energize a signal 46 preferably mounted on the dashboard and assuming the form of a bulb although it could be a buzzer.

This apparatus is arranged so that when the valve 12 is opened, the parts are as shown in FIGS. 2 and 3, but when the valve 12 turns to closed position, the radial leaf 40 will bear on one of the pins 38 causing it to move against the action of spring 44 and energize the circuits of the lamp 46 by closing the switch at 42. However as soon as the valve 12 opens once more, the plunger 34 is moved in the opposite direction either by the spring 44 or by the other finger 38 so as to allow the normally open circuit switch 42 to once more open, thus turning olf lamp 46.

The elfect of the apparatus above described is that when the valve 12 becomes closed, particularly for instance as in cold weather, and will not open, the lamp 46 is energized so that the operator of the vehicle is well aware of the fact that the valve is closed. He then pushes the push-button switch or the like 32 energizing the heating coil at 30, warming the bimetallic strip and causing it to expand, in turn turning the crank 16 and the shaft 14 and the valve 12 to open the latter, at which point the lamp goes out. As soon as the lamp goes out, the operator of the vehicle can deenergize the electric heating coil by opening the switch 32, i.e., by taking his finger off of the button, and then turning the key for the ignition, starting the car engine.

In the operation of this device, the operator of the vehicle will first turn on the ignition and step on the gas. If it is a cold morning, this will not result in starting the car but instead the valve in the automatic choke will snap shut and it will not open because it needs heat to open it. This valve must therefore be mechanically opened by the operator who has to remove the air cleaner to get at it and then place an object down into the air intake to push the valve open and hold it open. Then he can start the car by the usual key, etc.

However by the present invention the signal on the dishboard will immediately go on when the valve in the automatic choke is closed so that the operator is immediately apprised of the fact that this valve is closed and that is why the car will not start. He then pushes the button to energize the heating coil in the cap that holds the bimetallic strip and just as soon as this valve opens enough so that air can come into the carburetor for the 3 car to start, the signal goes off and he therefore deenergizes the heating coil merely by taking his finger oil of the button switch and then he can start the car in the usual manner.

The advantages of this invention are apparent. In the first place the operator of the car is enabled to start the car quickly and easily without leaving his seat. Also flooding is prevented and therefore damages which result from flooding are avoided such as the gasoline in the crankcase, etc., all as is well known to those skilled in the art. Furthermore, the usual bucking and bumping due to a flooded carburetor is avoided.

Instead of the switch 42 and plunger 34, the rod 14 could have mounted on it a conventional mercury type switch which would open and close upon rocking of the rod 14.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claim, but what I claim is:

An internal combustion engine carburetor having an automatic choke including a movable valve in the air intake, a rod to operate the valve, a lever to operate the rod, a bimetallic strip which contracts and expands under difierent degrees of heat, said bimetallic strip having a free end connected to said lever and operating the same to move the valve, a heating element located in close proximity to said bimetallic strip, and means convenient to the operator of the vehicle for energizing the heating element so as to heat the bimetallic strip and .thereby cause the valve to open, and an electric signal device, a plunger having a position to energize the signal device, means including pins connecting the plunger to said valve for movement of the plunger according to the valve position, an electric switch actuated by the plunger in its signal energizing position which in turn energizes the signal, said valve thereby causing the signal device to be energized in its position wherein the automatic choke valve is completely closed, and means including spring deenergizing the signal when the automatic choke valve becomes completely open.

References Cited by the Examiner UNITED STATES PATENTS 1,297,369 3/1919 Lepper 219-207 X 2,071,633 2/ 1937 Hunt. 3,161,787 12/1964 Van Saan. 3,179,098 4/ 1965 Highley et al.

FOREIGN PATENTS 564,563 10/ 1944 Great Britain. 799,345 8/ 1958 Great Britain.

HARRY B. THORNTON, Primary Examiner.

RONALD R. WEAVER, Examiner. 

